I have a 87 F36 twin 454 crusaders. Looking to get some intel on what others are running for props. Called Bob, he said the boat calls for 20x21 no cup, which is what I have. I can only get 3700 max RPM. Boat planes at about 2600 and I cruise at about 2800 and do about 16 knots at that RPM, if I push to 3000 I'm doing about 20 knots. I'm happy with this lower RPM and speed, but just wondering why I can't get to 4000. I have new carbs and engines run very smooth.
Any success with a different prop size? Do other F36's with crusaders run like mine?
Prop Size 1987 F36
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- prowlersfish
- 2025 Gold Support
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Re: Prop Size 1987 F36
You will do better with 20x20 . Your boat is not as light as it used to be when it was new
Boating is good for the soul
77/78 TROJAN F36 Conv.
6BTA Cummins diesels
Life is to short for a ugly boat
77/78 TROJAN F36 Conv.
6BTA Cummins diesels
Life is to short for a ugly boat

Re: Prop Size 1987 F36
Thanks for the reply. I'm not sure what you mean but it's not as light when it was new? Enlighten me. You think my fuel consumption will go down too?
- prowlersfish
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Re: Prop Size 1987 F36
Gear ,toys, fishing gear, water absorption it all adds up . I doubt you will see any loss of mpg . And it will make life easier on the engines .
From what I have seen most boats leave the factory propped to the limit or slightly over propped .
From what I have seen most boats leave the factory propped to the limit or slightly over propped .
Boating is good for the soul
77/78 TROJAN F36 Conv.
6BTA Cummins diesels
Life is to short for a ugly boat
77/78 TROJAN F36 Conv.
6BTA Cummins diesels
Life is to short for a ugly boat

- WayWeGo
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- Location: Oakton, VA / Rhode River - Chesapeake Bay
Re: Prop Size 1987 F36
FWIW, we are running 18.5x19 no cup and barely get to max RPM at the beginning of the season. I really need to put the boat on a diet and get some of the junk off it!
1975 F-36 Convertible
Twin Chrysler 440's
Twin Chrysler 440's
Re: Prop Size 1987 F36
Thanks for the advice I'll redo the props to 20x20 next year. Hopefully I can reach 4000
- prowlersfish
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- Joined: Sat Nov 05, 2005 6:56 pm
- Location: Lower Chesapeake Bay ,Va
Re: Prop Size 1987 F36
That seems on the small size for props . But it is what it isWayWeGo wrote:FWIW, we are running 18.5x19 no cup and barely get to max RPM at the beginning of the season. I really need to put the boat on a diet and get some of the junk off it!
Boating is good for the soul
77/78 TROJAN F36 Conv.
6BTA Cummins diesels
Life is to short for a ugly boat
77/78 TROJAN F36 Conv.
6BTA Cummins diesels
Life is to short for a ugly boat

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- Ultimate User
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- Location: Canton, TX Boat on TEXOMA
Re: Prop Size 1987 F36
My tri cabin weighed 16000 lbs with 200 gals of gas and half full water tank when I pulled it from water to clean bottom. Have not really filled boat with all the other goodies. My best speed is 25 mph and I have 20x17 at 3600 to 3800 rpm. Will post a picture tomorrow on other computer.
Larry Eddington
1984 F-36 Tri Cabin "The Phoenix II"
1978 F-28 "The Phoenix"
Fish Master 2350 Bay Boat
9.5' Dink
1984 F-36 Tri Cabin "The Phoenix II"
1978 F-28 "The Phoenix"
Fish Master 2350 Bay Boat
9.5' Dink